Elastomeric materials have been used in numerous applications to improve the fit or function of a garment or product. For example, elastomeric materials have been used in diapers, feminine care products, adult care products, health care garments and industrial protective garments. In many applications, elastic materials are bonded to one or more other layers in order to form laminated structures for use in these garments and products.
Elastic composites which are suitable for use in such products have been formed by bonding an elastic polymer layer in the form of a film, foam, nonwoven web or parallel strands, to one or more nonwoven facing layers. A particularly suitable elastic composite is a “neck-bonded laminate” (“NBL”). In this type of elastic composite, an elastic layer is bonded to one or two “necked” facing layers while the elastic layer is relaxed. The facing layer(s) are extended or “necked” to reduce their dimensions in the direction orthogonal to the extension. A “necked” material or web refers to a material or web which has been constricted in at least one dimension by processes such as, for example, drawing. Neck-bonded laminates can have cross-directional stretch and recovery properties. Neck-bonded laminates are described, for instance, in U.S. Pat. No. 5,853,881 to Estey et al., U.S. Pat. No. 4,965,122 to Morman, and U.S. Pat. No. 6,001,460 to Morman et al., and U.S. Pat. No. 5,789,065 to Haffner et al., which are incorporated herein by reference.
In the construction of such garments or products, the highly elastic components are typically attached to components which are stronger with less or no elasticity. The attachment between the highly elastic component and the stronger less elastic component is often critical and complicated. Thus, there is a need for the production of a continuous material with a highly elastic region and a stronger less elastic region offers good opportunities for significant product simplification and improvement by eliminating this interface.
The present invention addresses this need by providing an elastic material and process which forms a highly elastic region and a region which has good strength for improved processability of the laminate into a product.